Silo elevator

ABSTRACT

A silo elevator including a first stationary section for support from an upper portion of one side of a silo and a second section for movement up and down that one side of the silo. One of the sections includes guide means from which the central portion of an elongated flexible tension member is supported for longitudinal shifting relative thereto and the other section includes a pair of winding members driven at the same effective peripheral speed and upon which the opposite end portions of the tension member are wound. Further, the tension member and first section include coacting abutment means spaced along the path of movement of the central portion of the tension member relative to the guide means for limiting longitudinal shifting of the tension member relative to the guide means.

United States Patent Badding June 27, 1972 [54] SILO ELEVATOR [72] Inventor: Leonard J. Badding, Vinton, Iowa [73] Assignee: Veda, lnc., Long Lake, Minn. [22] Filed: Nov. 13, 1969 l 21 Appl. No.: 876,528

1,833,243 11/1931 Dunn ..187/95 2,686,659 8/1954 Bittner. ...254/l86 H 2,781,865 2/1957 Brott 187/6 Primary Examiner-Evon C. Blunk Assistant Examiner-Merle F. Maffei AttorneyBurd, Bradlock & Bartz [57] ABSTRACT A silo elevator including a first stationary section for support from an upper portion of one side of a silo and a second section for movement up and down that one side of the silo. One of the sections includes guide means from which the central portion of an elongated flexible tension member is supported for longitudinal shifting relative thereto and the other section includes a pair of winding members driven at the same effective peripheral speed and upon which the opposite end portions of the tension member are wound. Further, the tension member and first section include coacting abutment means spaced along the path of movement of the central portion of the tension member relative to the guide means for limiting longitudinal shifting of the tension member relative to the guide means.

23 Claims, 8 Drawing Figures PATENTEnJum 1972 3,672,471

SHEET 10F 4 Fig Fig. 8

Leonard J. Budding INVENTOR BY Qwaarfiu WM Mzsm PATENTEDJUHZ? m2 3. 672.471

sum 2 or 4 Fig.2

44 Leonard J. Budding I38 INVENTOR.

PATENTEDJUHN m2 8.672.471

saw u or 4 Leonard J. Budding INVENTOR.

BY W W SILO ELEVATOR BACKGROUND OF INVENTION A conventional silo is provided with a vertical chute on the exterior of the silo having an open lower end spaced above the ground and into which vertically spaced doorways in the silo wall upon which the chute is mounted open. The doorways are provided with removable closures therefor and some silos are further provided with encircling reinforcing bands which pass about the outer surfaces of the silo at elevations between adjacent doorways opening into the chute.

The elevator of the instant invention utilizes these basic components of a conventional silo in providing an elevator construction for carrying persons up through the silo chute to any desired elevation.

SUMMARY OF INVENTION The elevator construction includes a pair of circumferentially spaced vertically extending guide rails having braces secured therebetween which are supported from the portions of the bands encircling the silo disposed on opposite sides of the doorways which open into the chute. A carriage member is supported for vertical movement along the guide rails and includes a ratchet-type brake dog for engagement with the next lowest reinforcing band upon controlled descent of the carriage. Further, a support bracket is provided for sup port from the side wall of the silo within the upper end of the chute and the support bracket includes guide means from which the central portion of an elongated flexible tension member is supported for limited longitudinal shifting. The carriage includes a pair of winding members driven at the same peripheral speed and about which the opposite end portions of the tension member are wound. In this manner, winding the end portions of the tension member upon the winding members will cause the carriage to be elevated along the rails and any slight difference in the effective circumference of the winding members is readily compensated for by the mid-portion of the tension member being longitudinally shiftable, between limits, relative to the guide means at the upper end of the silo from which the mid-portion of the tension member is supported.

The main object of this invention is to provide a silo elevator which may be utilized by persons to gain access to the interior of a silo at any elevation thereof spaced vertically therealong.

Another object of this invention is to provide a silo elevator in accordance with the preceding object and constructed in a manner whereby it may be readily supported from an associated silo without modification of any portions of the existing silo.

A still further object of this invention is to provide a silo elevator including built-in safety features and double suspension ropes whereby the elevator is rendered as safe as possible.

Another important object of this invention is to provide a silo elevator whose structural features adapt it for use in conjunction with substantially all types of silos provided with an external vertical chute.

A final object of this invention to be specifically enumerated herein is to provide a silo elevator in accordance with the preceding objects which will conform to conventional forms of manufacture, be of simple construction and easy to 'use so as to provide a device that will be economically feasible, long lasting and relatively trouble free in operation.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a fragmentary side elevational view of a silo with which the elevator has been operatively associated;

FIG. 2 is a front elevational view of the silo with a portion of the upper end of the chute being broken away to more clearly illustrate the manner in which the elevator is supported from the silo;

FIG. 3 is a fragmentary front elevational view of the silo with the chute removed and on somewhat of an enlarged scale;

FIG. 4 is a fragmentary vertical sectional view taken substantially upon the plane indicated by the section line 4-4 of FIG. 3;

FIG. 5 is a fragmentary enlarged top plan view illustrating the manner in which the upper support bracket for the elevator is supported from the upper end of the silo;

FIG. 6 is a fragmentary horizontal sectional view taken sub stantially upon the plane indicated by the section line 6-6 of FIG. 3;

FIG. 7 is a perspective view of the support bracket by which the mid-portion of the tension member of the elevator is supported from the upper end of the silo; and

FIG. 8 is a perspective view of the carriage portion of the silo elevator.

Referring now more specifically to the drawings, the numeral 10 generally designates a conventional form of silo which includes a cylindrical upright body 12 mounted on a suitable base 14 and is provided with a top wall structure 16 at its upper end. The silo 10 includes a vertical chute 18 which extends along its front wall portion and the upper end of the chute 18 opens into the top wall structure 16. The chute l8 terminates downwardly a spaced distance above the base 14 and a retractable chute deflector 20 is operatively associated with the lower end of the chute 18. The chute deflector 20 is held in an upwardly pivoted out-of-the-way position by means of a lift line 22 passed over a sheave 24 supported from the chute 18 and the deflector 20 is supported for swinging from the inactive out-of-the-way position illustrated in FIG. 1 of the drawings to an operative position beneath the chute 18 by means of a pair of swing straps 26 secured between the chute deflector 20 and the chute 18. The chute deflector 20 includes a wall 28 which is downwardly and outwardly inclined when the deflector 20 is in its operative position beneath the lower end of the chute l8 and the deflector 20 is open as at 30 for discharging material falling down the chute 18 forwardly and outwardly of the front side of the base 14 when the deflector 20 is in its operative position.

The silo 10 includes horizontally disposed circumferentially extending reinforcing bands or rods 32 spaced vertically apart throughout substantially the entire vertical height of the silo 10 below the top wall structure 16 and the front wall of the silo 10 includes a plurality of vertically spaced door openings 34, see FIG. 3, for providing access into the interior of the silo 10 through the front wall thereof at various elevations spaced vertically along the front wall. The door openings include closure doors 36 removably secured therein and each of the doors 36 includes an outwardly projecting step 38.

The foregoing comprises a description of a conventional form of silo whose front wall may be climbed by means of the steps 38 until the desired height is achieved at which point the desired door 36 may be opened to provide access to the interior of the silo 10. Further, it will be noted that the upper doors and upper steps 38 are enclosed within the chute 18.

The silo elevator is referred to in general by the reference numeral 40 and includes a first stationary support section illustrated in FIG. 7 of the drawings and generally referred to by the reference numeral 42 and a second carriage section illustrated more clearly in FIG. 8 and generally referred to by the reference numeral 44. The support section 42 includes a pair of downwardly opening generally inverted U-shaped bracket portions 44 including depending legs 46 and 48 interconnected at their upper ends by means of a bight portion 50. Each of the bight portions 50 includes a forward extension 52 and the forward ends of the forward extensions 52 are interconnected by means of a plate-like inverted U-shaped support plate 54 including depending legs 56 and an upper bight portion 58. The opposite ends of the upper marginal portion of the support plate 54 are secured to the forward ends of the extensions 52 and it may be seen from FIGS. 5 and 7 of the drawings that the opposite surfaces of the legs 46 and 48 extend generally along chords of arcs whose centers of curvature correspond to the center axis of the upstanding body 12 of the silo 10. Accordingly, the bracket portions 44 may be readily removably embracingly engaged with the upper marginal portion of the front wall of the body 12 within the upper end of the chute 18 for support of the support section 42 from the upper end of the silo body 12 with the support plate 54 spaced slightly outwardly of the outer surface of the front wall of the body 12.

The support plate 54 has a pair of pulleys 60 supported from the upper ends of the legs 56 thereof by means of outwardly projecting pivot shafts 62 carried by the legs 56 upon which the pulleys 60 are joumaled. In addition, the upper end of each leg 56 includes a forwardly and outwardly projecting arcuate guard 64 which closely overlies the remote upper sectors of the pulleys 60. Also, the mid-portion 66 of an elongated flexible tension member 68 is passed over the pulleys 60 and beneath theguards 64 with the opposite end portions of the tension member 68 depending downwardly from the remote sides of the pulleys 60. The tension member 68 has a first abutment 70 secured thereto intermediate the pulleys 60 and also a pair of abutments 72 secured thereto in locations spaced below the pulleys 60.

A track assembly for the carriage section 44 is generally referred to by the reference numeral 74 and includes a pair of upstanding parallel and oppositely opening C-shaped channel members 76 interconnected at corresponding points spaced longitudinally therealong by means of horizontal transverse braces 78 secured to the rear edges of the channel members 76. From FIGS. 3 and 4 of the drawings it will be noted that the transverse braces 78 are spaced along the track assembly 74 so as to be in horizontal registry with the spacing between adjacent doors 36 whereby the removal of a selected door 36 is not interfered with. Further, each of the transverse braces 78 has a pair of J-bolts 80 secured through its opposite ends by means of threaded fasteners 82 spaced slightly inwardly of the channel members 76 and the hooked end of each J-bolt 80 is clampingly engaged about the corresponding circumferential bracing rod 32 secured about the body 12 of the silo 10, see FIGS. 4 and 6.

In this manner, the track assembly 74 is rigidly supported on the exterior of the front wall of the body 12 with the upper end of the track assembly 74 disposed within the chute 18. However, as can be seen from FIGS. 1 and 2 of the drawings, the track assembly 74 extends downward below the lower end of the chute 18 and the lower ends of the channel members 76 may rest upon the upper surface of the base 14 for supporting the entire weight of the track assembly 74 from the base 14. In this manner, the J-bolts 80 are required only to hold the track assembly 74 against the exterior surface of the front wall of the body 12 of the silo 10.

The carriage structure 44 includes a pair of upstanding and parallel opposite side members 86 interconnected at their upper ends by means of a transverse brace 88 and at their lower ends by means of a transverse brace 90. Further, the lower end of the carriage structure 44 includes a semi-cylindrical support portion 92 whose opposite ends are secured to the remote outer surfaces of the side members 86 and from whose outer surfaces a pair of rearwardly projecting support brackets 94 are supported. The rear ends of the rearwardly projecting support brackets 94 have guide wheels 96 journaled from their inner surfaces and a similar pair of support brackets 98 are secured to the outer surfaces of the upper ends of the support members 86 and have guide wheels 100 journaled therefrom. However, the support brackets 98 include forward extensions 102 from which the opposite endsof a shaft 104 are joumaled. The shaft 104 has a double winding spool 106 mounted thereon for rotation therewith and the left hand end of the shaft 104 is driven by a gear head assembly 108 supported from the left hand support bracket 98 and driven by an electric motor 110. The motor 110 is of the reversing type and is suitably electrically connected to a reversing switch 112 removably supported from the left hand support member 86 by means of a coiled multi-conductor wire 114. Current is supplied to the reversing switch 112 through an extension cord 116 which extends downwardly to the lower end of the body 12 of the silo 10 and may be carried by a spring wound reel (not shown).

The lower end portions of the tension member 68 are wound on the opposite ends of the winding spool 106 for rotation therewith and accordingly, both end portions of the tension member 68 are wound onto and from the winding spool 106.

The support portion 92 includes a lower inwardly directed flange 120 against which the outer peripheral portion of a swingable platform 122 abuts when the platform 122 is in its operative position. The platform 122 includes a pair of mounting brackets 124 which are pivotally supported from the lower ends of the side members 86 as at 124 and it may be seen from FIG. 4 of the drawings that the platform 122 may be swung from the operative solid line position to the raised inoperative phantom line position and secured in the raised inoperative position by means of a hook 128 carried by the right hand side member 86. Further, the side members 86 have the opposite ends of a cross shaft 130 journaled therethrough and the end portions of the cross shaft 130 have ratchet dog anns 132 mounted thereon. The arms 32 are swingable from the retracted solid line position thereof illustrated in FIG. 4 of the drawings to the phantom line position illustrated in FIG. 4 in order to catch each transverse brace 78 in the case of uncontrolled falling of the carriage assembly 44. In addition, the arms 132 may be swung to the operative positions thereof illustrated in FIG. 4 of the drawings to support the carriage section 44 in selected elevations along the front wall of the body 12 independent of the tension member 68. I

With attention now invited more specifically to FIGS. 3, 4 and 8 of the drawings there may be seen a railing structure 134 which includes an arcuate upper horizontal section 136 and a vertical section 138 whose upper end is secured to one end of the arcuate section 136. The free end of the arcuate section 136 is secured to the right hand side member 86 as at 140 and the lower end of the vertical section 138 is secured to the support pottion 92 as at 142. In addition, one end of a link chain section 144 is secured to the railing 134 at the juncture between the arcuate section 136 and the vertical section 138 and the other end of the link chain section is releasably engageable with a hook 146 provided for the purpose on the left hand side member 86.

The carriage section 44 is supported from the track-assembly 74 with the wheels 96 and embracingly received within the channel members 76. Further, an expansion spring 148 is provided and connected between the right hand side member 86 and the right hand arm 132 for yieldingly urging the arms 132 to the phantom line positions thereof illustrated in FIG. 4 of the drawings. However, the right hand arm 132 includes a hook 150 which may be releasably engaged with the right hand side member 86 in order to retain the arms 132 in the inoperative positions thereof illustrated in solid lines in FIGS. 4 and 8 of the drawings.

In operation, a person desirous of entering the silo 10 through one of the upper door openings 134 positions himself on the platform 122 after the latter has been pivoted to the operative position illustrated in solid lines in FIG. 4 of the drawings. Then, the person standing on the platform 122 engages the free end of the link chain section 144 with the hook 146 and operates the reversing switch 112 to cause actuation of the electric motor in the proper direction to wind the lower end portions of the tension member 86 on the winding spool 106. This of course will cause the carriage section 44 to move upwardly along the track structure 74. Of course, before actuating the electric motor, the person operating the elevator 40 releases the hook 150 in order that the arms 132 will be yieldingly urged to the phantom line positions thereof illustrated in FIG. 4 of the drawings so as to be momentarily operative to check uncontrolled descent of the carriage section 44. When the operator of the elevator 40 reaches the desired level, the switch 112 is actuated to terminate operation of the electric motor and the operator may then remove the desired door 36 and enter the silo 10. When descending, the operator again positions himself on the platform 122, closes the door 136 and grabs the handle 152 on the right hand arm 132 so as to manually swing the arms 132 from the phantom line positions thereof illustrated in FIG. 4 to the solid line positions thereof. Thereafter, the operator may actuate the switch 112 so as to cause operation of the motor 110 in the opposite direction and the carriage section 44 to be lowered along the track assembly 74.

Of course, the elevator 40 may be used on a silo which does not include an exterior chute such as chute l8, inasmuch as the elevator 40 is free of direct connection with and support from the chute 18.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed is:

1. An elevator for use with a silo and like structures having an upper wall portion comprising a first support section mountable on the upper wall portion of the silo, a second carriage section movable up and down the silo, one of said sections including guide means, said guide means having a pair of laterally spaced pulleys rotatable on separate generally parallel means, an elongated flexible tension member having end portions and a mid-portion trained over said pulleys for guided shifting of the tension member relative to the guide means, fixed means on said one section located adjacent said pulleys to retain the tension member on said pulleys, the other section including reversible driven winding means, the end portions of said tension member extending toward said winding means and being partially wound on said winding means, and first abutment means secured to the portion of the tension member between the pulleys and second abutment means secured to the portions of the tension members leaving the pulleys, said first and second abutment means engageable with said pulleys and fixed means to establish limits of shifting of said tension member relative to said guide means to provide a safety stop in the event of a cable breakage.

2. The combination of claim 1 wherein said one section comprises said first support section.

3. The combination of claim 1 including a pair of parallel upstanding guide rails, a plurality of horizontal cross braces extending and secured between said rails at elevations spaced longitudinally therealong, said braces including means intermediate said rails adapted for attachment to a wall portion of said silo, said second carriage section including follower means guidingly engaged with said rails for movement therealong.

4. The combination of claim 3 wherein said carriage section includes a lift platform projecting outwardly to one side of a plane containing said rails, the edge portion of said platform adjacent said plane being pivotally supported from said carriage section for oscillation of said platform about a horizontal axis generally paralleling said plane between a generally horizontal position and an upstanding position spaced closely adjacent and generally paralleling said plane.

5. The combination of claim 1 including a pair of parallel upstanding guide rails, a plurality of horizontal cross braces extending and secured between said rails at elevations spaced longitudinally therealong, said braces including means intermediate said rails for attachment to a wall portion of said silo, said second carriage section including follower means guidingly engaged with said rails for movement therealong,

said carriage section including a pivoted ratchet-type safety pawl swingable through said plane for engagement with the outer surface of the wall of said silo.

6. The combination of claim 1 wherein said first support section includes generally aligned spaced apart inverted U- shaped mounting portions adapted for downwardly embracingly engaging circumferentially spaced portions of the upper marginal edge of the wall portion of said silo.

7. The combination of claim 6 including a pair of parallel upstanding guide rails, a plurality of horizontal cross braces extending and secured between said rails at elevations spaced longitudinally therealong, said braces including means intermediate said rails adapted for attachment to a wall portion of said silo, said second carriage section including follower means guidingly engaged with said rails for movement therealong.

8. The combination of claim 7 wherein said carriage section includes a lift platform projecting outwardly to one side of a plane containing said rails, the edge portion of said platform adjacent said plane being pivotally supported from said carriage section for oscillation of said platform about a horizontal axis generally paralleling said plane between a generally horizontal position and an upstanding position spaced closely adjacent and generally paralleling said plane.

9. The combination of claim 1 wherein said carriage section includes a pivoted safety pawl swingable to a position for engagement with fixed means to hold the carriage section at a selected elevation.

10. The combination of claim 1 wherein said winding means include a pair of coaxial winding spools supported for simultaneous rotation in the same direction.

11. The combination of claim 1 including upstanding elongated track means for support from the outer wall surfaces of said silo, said second carriage section being engaged with said elongated track means for guided movement therealong.

12. The combination of claim 11 wherein said track means have lower end portions in engagement with a stationary support.

13. The combination of claim 1 wherein said winding means is mounted on upper portions of the carriage section, said tension member located in substantial linear extension between the winding means and the guide means.

14. The combination of claim 1 wherein said pulleys are rotatably mounted on shaft means secured to a plate member and said fixed means are secured to the plate member and extend adjacent outer peripheral portions of the pulleys.

15. The combination of claim 1 wherein the fixed means are arcuate guards extended adjacent outer peripheral portions of the pulleys.

16. An elevator usable with a structure such as a silo or the like with a generally upright body having an upper portion comprising fixed support means attachable to the upper portion of the body, a carriage movable up and down relative to said body, flexible cable means having end portions, holding means on the support means operatively connecting a portion of the cable means to the support means, said holding means having a pair of spaced pulleys carrying the cable means, generally parallel means rotatably mounting said pulleys, and fixed means located adjacent said pulleys to retain the cable means on the pulleys, abutment means secured to the cable means and engageable with the fixed means and pulleys to limit movement of the cable means relative to the pulleys, spool means rotatably mounted on the carriage, said ends of the cable means being connected to the spool means, and drive means on the carriage for rotating the spool means in one direction to wind the cable means on the spool means and selectively rotating the spool means in the opposite direction to unwind the cable means from the spool means; said abutment means includes first abutment means secured to the middle portion of the cable means located between the pulleys and second abutment means secured to the portions of the cable means leaving the pulleys to provide a safety stop in the event of cable breakage.

17. The elevator of claim 16 including a generally upright track assembly, means movably mounting the carriage on the track assembly, and means mounting the track assembly on the body.

18. The elevator of claim 17 wherein the track assembly has lower ends in engagement with a stationary support.

19. The elevator of claim 16 wherein the spool means is mounted on the upper portion of the carriage, said cable means located in substantial linear extension between the spool means and holding means.

20. An elevator usable with a silo or the like with a generally upright body having an upper portion comprising a fixed support section attachable to the upper portion of the body, a carriage section movable up and down relative to said body, a generally upright track assembly, means mounting the track assembly on the body, means movably mounting the carriage section on the track assembly, one of said sections including guide means, said guide means having pulley means, means rotatably mounting said pulley means, elongated flexible cable means trained over said pulley means, fixed means on said one section located adjacent said pulley means to retain the cable means on said pulley means, spool means rotatably mounted on the other section, said cable means connected to the spool means and located in substantial linear extension between the spool means and the pulley means, and drive means for rotating the spool means in one direction to wind the cable means on the spool means and selectively rotating the spool means in the opposite direction to unwind the cable means from the spool means, and abutment means secured to the cable means and engageable with the fixed means and pulley means to limit movement of the cable means relative to the pulley means; wherein said abutment means include first abutment means secured to the portion of the cable means located on one side of said pulley means and second abutment means secured to the portions of the cable means on the other side of the pulley means to provide a safety stop in the event of cable breakage.

21. The elevator of claim 20 wherein the track assembly has lower ends in engagement with a stationary support.

22. The elevator of claim 20 wherein said pulley means are rotatably mounted on shaft means secured to a plate member and said fixed means are secured to the plate member and extend adjacent outer peripheral portions of the pulley means.

23. The elevator of claim 20 including an arm means swingably mounted on the carriage, said arm means movable in a position for engagement with fixed means to support the carriage at a selected elevation.

i K i l l 

1. An elevator for use with a silo and like structures having an upper wall portion comprising a first support section mountable on the upper wall portion of the silo, a second carriage section movable up and down the silo, one of said sections including guide means, said guide means having a pair of laterally spaced pulleys rotatable on separate generally parallel means, an elongated flexible tension member having end portions and a midportion trained over said pulleys for guidEd shifting of the tension member relative to the guide means, fixed means on said one section located adjacent said pulleys to retain the tension member on said pulleys, the other section including reversible driven winding means, the end portions of said tension member extending toward said winding means and being partially wound on said winding means, and first abutment means secured to the portion of the tension member between the pulleys and second abutment means secured to the portions of the tension members leaving the pulleys, said first and second abutment means engageable with said pulleys and fixed means to establish limits of shifting of said tension member relative to said guide means to provide a safety stop in the event of a cable breakage.
 2. The combination of claim 1 wherein said one section comprises said first support section.
 3. The combination of claim 1 including a pair of parallel upstanding guide rails, a plurality of horizontal cross braces extending and secured between said rails at elevations spaced longitudinally therealong, said braces including means intermediate said rails adapted for attachment to a wall portion of said silo, said second carriage section including follower means guidingly engaged with said rails for movement therealong.
 4. The combination of claim 3 wherein said carriage section includes a lift platform projecting outwardly to one side of a plane containing said rails, the edge portion of said platform adjacent said plane being pivotally supported from said carriage section for oscillation of said platform about a horizontal axis generally paralleling said plane between a generally horizontal position and an upstanding position spaced closely adjacent and generally paralleling said plane.
 5. The combination of claim 1 including a pair of parallel upstanding guide rails, a plurality of horizontal cross braces extending and secured between said rails at elevations spaced longitudinally therealong, said braces including means intermediate said rails for attachment to a wall portion of said silo, said second carriage section including follower means guidingly engaged with said rails for movement therealong, said carriage section including a pivoted ratchet-type safety pawl swingable through said plane for engagement with the outer surface of the wall of said silo.
 6. The combination of claim 1 wherein said first support section includes generally aligned spaced apart inverted U-shaped mounting portions adapted for downwardly embracingly engaging circumferentially spaced portions of the upper marginal edge of the wall portion of said silo.
 7. The combination of claim 6 including a pair of parallel upstanding guide rails, a plurality of horizontal cross braces extending and secured between said rails at elevations spaced longitudinally therealong, said braces including means intermediate said rails adapted for attachment to a wall portion of said silo, said second carriage section including follower means guidingly engaged with said rails for movement therealong.
 8. The combination of claim 7 wherein said carriage section includes a lift platform projecting outwardly to one side of a plane containing said rails, the edge portion of said platform adjacent said plane being pivotally supported from said carriage section for oscillation of said platform about a horizontal axis generally paralleling said plane between a generally horizontal position and an upstanding position spaced closely adjacent and generally paralleling said plane.
 9. The combination of claim 1 wherein said carriage section includes a pivoted safety pawl swingable to a position for engagement with fixed means to hold the carriage section at a selected elevation.
 10. The combination of claim 1 wherein said winding means include a pair of coaxial winding spools supported for simultaneous rotation in the same direction.
 11. The combination of claim 1 including upstanding elongated track means for support from the outer walL surfaces of said silo, said second carriage section being engaged with said elongated track means for guided movement therealong.
 12. The combination of claim 11 wherein said track means have lower end portions in engagement with a stationary support.
 13. The combination of claim 1 wherein said winding means is mounted on upper portions of the carriage section, said tension member located in substantial linear extension between the winding means and the guide means.
 14. The combination of claim 1 wherein said pulleys are rotatably mounted on shaft means secured to a plate member and said fixed means are secured to the plate member and extend adjacent outer peripheral portions of the pulleys.
 15. The combination of claim 1 wherein the fixed means are arcuate guards extended adjacent outer peripheral portions of the pulleys.
 16. An elevator usable with a structure such as a silo or the like with a generally upright body having an upper portion comprising fixed support means attachable to the upper portion of the body, a carriage movable up and down relative to said body, flexible cable means having end portions, holding means on the support means operatively connecting a portion of the cable means to the support means, said holding means having a pair of spaced pulleys carrying the cable means, generally parallel means rotatably mounting said pulleys, and fixed means located adjacent said pulleys to retain the cable means on the pulleys, abutment means secured to the cable means and engageable with the fixed means and pulleys to limit movement of the cable means relative to the pulleys, spool means rotatably mounted on the carriage, said ends of the cable means being connected to the spool means, and drive means on the carriage for rotating the spool means in one direction to wind the cable means on the spool means and selectively rotating the spool means in the opposite direction to unwind the cable means from the spool means; said abutment means includes first abutment means secured to the middle portion of the cable means located between the pulleys and second abutment means secured to the portions of the cable means leaving the pulleys to provide a safety stop in the event of cable breakage.
 17. The elevator of claim 16 including a generally upright track assembly, means movably mounting the carriage on the track assembly, and means mounting the track assembly on the body.
 18. The elevator of claim 17 wherein the track assembly has lower ends in engagement with a stationary support.
 19. The elevator of claim 16 wherein the spool means is mounted on the upper portion of the carriage, said cable means located in substantial linear extension between the spool means and holding means.
 20. An elevator usable with a silo or the like with a generally upright body having an upper portion comprising a fixed support section attachable to the upper portion of the body, a carriage section movable up and down relative to said body, a generally upright track assembly, means mounting the track assembly on the body, means movably mounting the carriage section on the track assembly, one of said sections including guide means, said guide means having pulley means, means rotatably mounting said pulley means, elongated flexible cable means trained over said pulley means, fixed means on said one section located adjacent said pulley means to retain the cable means on said pulley means, spool means rotatably mounted on the other section, said cable means connected to the spool means and located in substantial linear extension between the spool means and the pulley means, and drive means for rotating the spool means in one direction to wind the cable means on the spool means and selectively rotating the spool means in the opposite direction to unwind the cable means from the spool means, and abutment means secured to the cable means and engageable with the fixed means and pulley means to limit movement of the cable means relative to the pulley means; wherein saId abutment means include first abutment means secured to the portion of the cable means located on one side of said pulley means and second abutment means secured to the portions of the cable means on the other side of the pulley means to provide a safety stop in the event of cable breakage.
 21. The elevator of claim 20 wherein the track assembly has lower ends in engagement with a stationary support.
 22. The elevator of claim 20 wherein said pulley means are rotatably mounted on shaft means secured to a plate member and said fixed means are secured to the plate member and extend adjacent outer peripheral portions of the pulley means.
 23. The elevator of claim 20 including an arm means swingably mounted on the carriage, said arm means movable in a position for engagement with fixed means to support the carriage at a selected elevation. 